session: Do not expect meaningful errno on non-UNIX

[libsigrok.git] / src / session.c

diff --git a/src/session.c b/src/session.c
index 20c9ce5fcea48aaa9bc75bb7cecf050276dbc829..138f4222263ebc6b1027df1b92348144429951d4 100644 (file)
--- a/src/session.c
+++ b/src/session.c
@@ -17,6 +17,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -358,6 +359,22 @@ SR_API int sr_session_trigger_set(struct sr_session *session, struct sr_trigger
        return SR_OK;
 }
 
+static gboolean sr_session_check_aborted(struct sr_session *session)
+{
+       gboolean stop;
+
+       g_mutex_lock(&session->stop_mutex);
+       stop = session->abort_session;
+       if (stop) {
+               sr_session_stop_sync(session);
+               /* But once is enough. */
+               session->abort_session = FALSE;
+       }
+       g_mutex_unlock(&session->stop_mutex);
+
+       return stop;
+}
+
 /**
  * Call every device in the current session's callback.
  *
@@ -370,9 +387,8 @@ SR_API int sr_session_trigger_set(struct sr_session *session, struct sr_trigger
  *              sources to fire an event on the file descriptors, or
  *              any of their timeouts to activate. In other words, this
  *              can be used as a select loop.
- *              If FALSE, all sources have their callback run, regardless
- *              of file descriptor or timeout status.
- *
+ *              If FALSE, return immediately if none of the sources has
+ *              events pending.
  * @retval SR_OK Success.
  * @retval SR_ERR Error occurred.
  */
@@ -380,6 +396,11 @@ static int sr_session_iteration(struct sr_session *session, gboolean block)
 {
        unsigned int i;
        int ret, timeout;
+       int revents;
+       gboolean stop_checked;
+       gboolean stopped;
+       struct source *source;
+       GPollFD *pollfd;
 #ifdef HAVE_LIBUSB_1_0
        int usb_timeout;
        struct timeval tv;
@@ -389,7 +410,6 @@ static int sr_session_iteration(struct sr_session *session, gboolean block)
 
 #ifdef HAVE_LIBUSB_1_0
        if (session->ctx->usb_source_present) {
-               timeout = block ? 0 : session->source_timeout;
                ret = libusb_get_next_timeout(session->ctx->libusb_ctx, &tv);
                if (ret < 0) {
                        sr_err("Error getting libusb timeout: %s",
@@ -403,34 +423,49 @@ static int sr_session_iteration(struct sr_session *session, gboolean block)
 #endif
 
        ret = g_poll(session->pollfds, session->num_sources, timeout);
+#ifdef G_OS_UNIX
+       if (ret < 0 && errno != EINTR) {
+               sr_err("Error in poll: %s", g_strerror(errno));
+               return SR_ERR;
+       }
+#else
+       if (ret < 0) {
+               sr_err("Error in poll: %d", ret);
+               return SR_ERR;
+       }
+#endif
+       stop_checked = FALSE;
+       stopped = FALSE;
+
        for (i = 0; i < session->num_sources; i++) {
-               if (session->pollfds[i].revents > 0 || (ret == 0
-                       && session->source_timeout == session->sources[i].timeout)) {
+               source = &session->sources[i];
+               pollfd = &session->pollfds[i];
+               revents = (ret > 0) ? pollfd->revents : 0;
+
+               if (revents > 0 || (ret == 0
+                       && session->source_timeout == source->timeout)) {
                        /*
                         * Invoke the source's callback on an event,
                         * or if the poll timed out and this source
                         * asked for that timeout.
                         */
-                       if (!session->sources[i].cb(session->pollfds[i].fd,
-                                       session->pollfds[i].revents,
-                                       session->sources[i].cb_data))
+                       if (!source->cb(pollfd->fd, revents, source->cb_data))
                                sr_session_source_remove(session,
-                                               session->sources[i].poll_object);
-               }
-               /*
-                * We want to take as little time as possible to stop
-                * the session if we have been told to do so. Therefore,
-                * we check the flag after processing every source, not
-                * just once per main event loop.
-                */
-               g_mutex_lock(&session->stop_mutex);
-               if (session->abort_session) {
-                       sr_session_stop_sync(session);
-                       /* But once is enough. */
-                       session->abort_session = FALSE;
+                                               source->poll_object);
+                       /*
+                        * We want to take as little time as possible to stop
+                        * the session if we have been told to do so. Therefore,
+                        * we check the flag after processing every source, not
+                        * just once per main event loop.
+                        */
+                       if (!stopped) {
+                               stopped = sr_session_check_aborted(session);
+                               stop_checked = TRUE;
+                       }
                }
-               g_mutex_unlock(&session->stop_mutex);
        }
+       if (!stop_checked)
+               sr_session_check_aborted(session);
 
        return SR_OK;
 }
@@ -856,6 +891,7 @@ SR_API int sr_session_source_add(struct sr_session *session, int fd,
 
        p.fd = fd;
        p.events = events;
+       p.revents = 0;
 
        return _sr_session_source_add(session, &p, timeout, cb, cb_data, (gintptr)fd);
 }
@@ -908,6 +944,7 @@ SR_API int sr_session_source_add_channel(struct sr_session *session,
 #else
        p.fd = g_io_channel_unix_get_fd(channel);
        p.events = events;
+       p.revents = 0;
 #endif
 
        return _sr_session_source_add(session, &p, timeout, cb, cb_data, (gintptr)channel);